Answer:
There is 17.1 kJ energy required
Explanation:
Step 1: Data given
Mass of ethanol = 322.0 grams
Initial temperature = -2.2 °C = 273.15 -2.2 = 270.95K
Final temperature = 19.6 °C = 273.15 + 19.6 = 292.75 K
Specific heat capacity = 2.44 J/g*K
Step 2: Calculate energy
Q = m*c*ΔT
⇒ m = the mass of ethanol= 322 grams
⇒ c = the specific heat capacity of ethanol = 2.44 J/g*K
⇒ ΔT = T2 - T1 = 292.75 - 270.95 = 21.8 K
Q = 322 * 2.44 * 21.8 = 17127.8 J = 17.1 kJ
There is 17.1 kJ energy required
The empirical formula gives the relative ratio of atoms in each element. Therefore, it simplifies the whole numbers. For example C2H6 can be reduced to CH3 because they share the greatest common factor (2). The answer to this question would be #1. C4H10 can be reduced to C2H5 because 4 and 10 are both divisible by 2. C2H5 can not be reduced any further. All of the other options do not have a greatest common factor making them a empirical formula.
Answer:
Option D. 4.02 kJ
Explanation:
A simple calorimetry problem
Q = m . C . ΔT
ΔT = Final T° - Initial T°
C = Specific heat capacity
m = mass
Let's replace the data
Q = 125 g . 2.42 J/g∘C . (34.8°C -21.5 °C)
Q= 4023.25 J
We must convert the answer to kJ
4023.25 J . 1kJ /1000 =4.02kJ
Answer:
1.99 x 10⁻¹⁸J
Explanation:
Given parameters:
Frequency of the wave = 3 x 10¹⁵Hz
Unknown:
Energy of the photon = ?
Solution:
To solve this problem, we use the expression below;
E = hf
Where E is the energy, h is the Planck's constant and f is the frequency
Now insert the parameters and solve for E;
E = 6.63 x 10⁻³⁴ x 3 x 10¹⁵ = 19.9 x 10⁻¹⁹J or 1.99 x 10⁻¹⁸J
